Theoretical study of hydrogen abstraction from dimethyl ether and methyl tert-butyl ether by hydroxyl radical

MP2/6-31G**//MP2/6-31G**, PMP2/6-31G**//MP2/6-31G**, MP4/6-311G(3df, 2p)//MP2/6-31G**, PMP4/6-311G(3df, 2p)//MP2/6-31G** and CCSD(T)/6-311++G**//MP2/6-31G** calculations have been used to investigate the H-abstraction reaction from CH3OCH3 (DME) whereas MP2/6-31G**//MP2/6-31G** and PMP2/6-31G**//MP2/6-31G** levels have been used to model the H-abstraction reaction from (CH3)(3)COCH3 (MTBE) by (OH)-O-.. The methodology used has been proved to be adequate to reproduce the experimental geometrical parameters for the reactants and the C-H bond energies. The reaction rate constants for DME, calculated using the transition state theory reproduce the reported experimental results. The fact that H-abstraction is favored from the methoxy group of MTBE in comparison to the tert-butyl group has also been reproduced.